Pisiform: Difference between revisions

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The pisiform is one of eight carpal bones that forms part of the wrist joint. It is a small pea-shaped bone. The name pisiform is derived from the Latin word "''pisum"''  which means pea. It can be felt on the anteromedial side of the wrist.  
The pisiform is one of eight carpal bones that forms part of the wrist joint. It is a small pea-shaped bone. The name pisiform is derived from the Latin word "''pisum"''  which means pea. It can be felt on the anteromedial side of the wrist.  


=== Structure  ===
== Structure  ==
'''The pisiform can be found on the anteromedial side of the wrist in the proximal row of the carpal bones. It can be easily palpated. The pisiform is a small sesamoid bone, enveloped in the flexor carpi ulnaris tendon.'''
The pisiform can be found on the anteromedial side of the wrist in the proximal row of carpal bones. It is a small sesamoid bone, enveloped in the flexor carpi ulnaris tendon and can be easily palpated from the exterior.<ref>Wadsworth CT. [https://www.jospt.org/doi/pdfplus/10.2519/jospt.1983.4.4.206 Clinical anatomy and mechanics of the wrist and hand]. Journal of Orthopaedic & Sports Physical Therapy. 1983 Apr 1;4(4):206-16.</ref>


== Function  ==
== Function  ==
'''The pisiform serves as an attachment for tendons and ligaments (1.1). As it is a sesamoid bone, it acts like a pulley that provides a smooth surface for the flexor carpi ulnaris tendon to glide over. The pisiform also forms part of the ulnar canal, or can also be referred to as the Guyon canal. It is a fibroosseus structure that forms a groove between the proximal side of the pisiform bone and the hook of the hamate'''<ref>Ramage JL, Varacallo M. [https://www.researchgate.net/profile/Matthew_Varacallo/publication/329717458_Anatomy_Shoulder_and_Upper_Limb_Hand_Guyon_Canal/links/5c17e48d299bf139c760571c/Anatomy-Shoulder-and-Upper-Limb-Hand-Guyon-Canal.pdf Anatomy, Shoulder and Upper Limb, Hand Guyon Canal].</ref>'''. (2.) The ulnar nerve and ulnar artery pass through this canal from the distal forearm into the hand. Thus the ulnar canal serves to protect the ulnar nerve and artery.''' 
The pisiform serves as an attachment for tendons and ligaments.<ref>Tang A. [https://www.researchgate.net/profile/Matthew_Varacallo/publication/329861188_Anatomy_Shoulder_and_Upper_Limb_Hand_Carpal_Bones/links/5c1d9a11299bf12be391373b/Anatomy-Shoulder-and-Upper-Limb-Hand-Carpal-Bones.pdf Anatomy, Shoulder and Upper Limb, Hand Carpal Bones].</ref> As it is a sesamoid bone, it acts as a pulley that provides a smooth surface for the flexor carpi ulnaris tendon to glide over. The pisiform also forms part of the ulnar canal or as otherwise called the Guyon canal. It is a fibroosseus structure that forms a groove between the pisiform and the hook of the hamate. The ulnar nerve and ulnar artery pass through this canal from the distal forearm into the hand.<ref>Ramage JL, Varacallo M. [https://www.researchgate.net/profile/Matthew_Varacallo/publication/329717458_Anatomy_Shoulder_and_Upper_Limb_Hand_Guyon_Canal/links/5c17e48d299bf139c760571c/Anatomy-Shoulder-and-Upper-Limb-Hand-Guyon-Canal.pdf Anatomy, Shoulder and Upper Limb, Hand Guyon Canal].</ref> 


=== Articulations  ===
== Articulations  ==
'''The pisiform does not form part of wrist movement, unlike all other carpal bones. It is situated where the ulna and the wrist connect, but articulates with the triquetrum only. It lies in a plane anterior and superficially to all other carpal bones.''' 
The pisiform does not form part of the wrist joint movement, unlike all other carpal bones. It is situated where the ulna and the wrist meet but articulates with the triquetrum only. It lies in a plane anterior and superficially to all other carpal bones. 


=== Muscle attachments  ===
== Muscle attachments  ==
'''Flexor Carpi Ulnaris – This is an extrinsic muscle that attaches to the pisiform, hook of hamate and 5<sup>th</sup> metacarpal. It allows wrist flexion and adduction. (1.2)'''
* Flexor Carpi Ulnaris – This is an extrinsic muscle that attaches to the pisiform, hook of hamate and 5th metacarpal. It allows wrist flexion and adduction.
 
* Abdutor digiti minimi – This is a hypothenar muscle. It allows abduction of the 5th finger and flexion of its proximal phalanx.
'''Transverse carpal ligament –'''
 
'''Abdutor digiti minimi – This is a hypothenar muscle. It allows abduction of the 5<sup>th</sup> finger and flexion of its proximal phalanx.'''


== Resources  ==
== Resources  ==

Revision as of 21:02, 17 February 2019

Nina Myburg

Top Contributors - Nina Myburg, Kim Jackson, Nikhil Benhur Abburi, Wendy Snyders and Leana Louw

Description[edit | edit source]

The pisiform is one of eight carpal bones that forms part of the wrist joint. It is a small pea-shaped bone. The name pisiform is derived from the Latin word "pisum" which means pea. It can be felt on the anteromedial side of the wrist.  

Structure[edit | edit source]

The pisiform can be found on the anteromedial side of the wrist in the proximal row of carpal bones. It is a small sesamoid bone, enveloped in the flexor carpi ulnaris tendon and can be easily palpated from the exterior.[1]

Function[edit | edit source]

The pisiform serves as an attachment for tendons and ligaments.[2] As it is a sesamoid bone, it acts as a pulley that provides a smooth surface for the flexor carpi ulnaris tendon to glide over. The pisiform also forms part of the ulnar canal or as otherwise called the Guyon canal. It is a fibroosseus structure that forms a groove between the pisiform and the hook of the hamate. The ulnar nerve and ulnar artery pass through this canal from the distal forearm into the hand.[3] 

Articulations[edit | edit source]

The pisiform does not form part of the wrist joint movement, unlike all other carpal bones. It is situated where the ulna and the wrist meet but articulates with the triquetrum only. It lies in a plane anterior and superficially to all other carpal bones. 

Muscle attachments[edit | edit source]

  • Flexor Carpi Ulnaris – This is an extrinsic muscle that attaches to the pisiform, hook of hamate and 5th metacarpal. It allows wrist flexion and adduction.
  • Abdutor digiti minimi – This is a hypothenar muscle. It allows abduction of the 5th finger and flexion of its proximal phalanx.

Resources[edit | edit source]

References[edit | edit source]

  1. Wadsworth CT. Clinical anatomy and mechanics of the wrist and hand. Journal of Orthopaedic & Sports Physical Therapy. 1983 Apr 1;4(4):206-16.
  2. Tang A. Anatomy, Shoulder and Upper Limb, Hand Carpal Bones.
  3. Ramage JL, Varacallo M. Anatomy, Shoulder and Upper Limb, Hand Guyon Canal.